Building structure



Aug. 23, 1938. R. G. GODSON I 2,128,137

BUILDING STRUCTURE Filed Dec. 8, 1934 3 Sheets-Sheet 2 KZZ Ga s 01s;

A zlvvuv'roR,

fi I I BY Q/TZwL/MJM ATTORNE YS.

R. G. GODSON BUILDING STRUCTURE Filed Dec. 8, 1934' 3 Sheets-Sheet 5Fla/6.

IN VENTOR,

ATTORNEYS.

Patented Au 23, 1938 UNITED STATES BUILDING STRUCTURE: ReginaldG.Godson, Toronto, Ontario, Canada Application December 8, 1934, SerialNo. 758,690

In Canada February 21, 1934 16 Claims.

The present invention relates to new and useful improvements in thedesign and erection of buildings and other structures, same comprising ageometric load-distribution system for placing loads economically onsupporting beams which carry the floors in the aforesaid structures.

In modern structures the cost of the floor-system, beams and columns isan important percentage of the total cost. The cost varies directly withthe weight of the structure, which in turn depends on the floor loadsand the span of the floor beams; and the span becomes a more importantfactor as the spacing of the columns increases. Lastly incidental designfeatures etc., such as ties, struts and bracing, add to the cost byproviding material that apart from the specified requirements forrigidity, perform no useful work supporting the floor loads of thestructures.

The usual types of floor construction, in use today, carry the floorloads directlyonto the supporting beams or marginal girders, Withoutattempting to place these loads on the supporting beams tobestadvantage.

In an ideal design, the floor loads should be transmitted directly tothe columns. Failing this, the next best arrangement would be tocarry-as much of the floor loads as possible to the ends of the marginalbeams or girders, thus reducing the bending moment and subsequentdeflection in the beams; resulting in a comparatively light and rigidstructure. Moreover, the floor loads should be transmitted to all thefloor beams, thus mak-- commonly employed; The present system makes itpossible to reduce the cost of building construction by using lighterand shallower beams and lighter slabs, and by decreasing the storyheights .50 of buildings. and other structures. It is applicable to anytype of construction, same' being. a geometric arrangement of the floorunits by means of which the floor loads are carried in ever increasingamounts towardsthe ends of the main 651, or marginal floor beams,instead of distributing them uniformly, overthe entire length of thesaid beams. This, isaccomplished by placing. a series of secondary beamsarranged in circumscribed relation? within the panel, and'a plurality ofcone centric groups of beams of smaller extent within the secondarybeams, as. will ,be explained herein.

' A comparison of the costs of floor slabs and main supporting beams,designed according to the, present system, with other floor systems. incommon. use shows that very'ia'ppreciable savings can be made in the'cost of construction. The actual amount of these savings due to reduced.depths ofslabs. and beams, in masonry walls, partiti'ons plastering,piping, wiring, etc., is also a substantial item in cost ofconstruction. The reduced dead loads. and building heights also effectsavings in columns and footings, particularly in structures designed toresist wind forces. I In bridge construction the concentrated wheelloads usually govern the design of the floor beams and stringers,although the slab itself may be reduced by the application of thepresent geometric load-distribution systemand such reduction in the slabdead loads'results in economy in design of the main trusses and girdersof the main structure. Tests of the present systemhave been made andsame have proven that the theory involved is substantiatedin practice.

In the accompanying drawings forming part of the present specification,I have illustrated the structural features embodied in my invention, inwhich:

Figure l is a plan view showing the layout'of a ring floor system, for atypical panel of a building or similar structure, in which is shown anumber of boundary or marginal girders, a series of secondary beamsarranged in circumscribed relation in the panel, and a plurality ofconcentric groups of beams of smaller extent, each group having itscentral'point coincidental with 40 that of one of the secondary beams.

Figures 2 and 3 showplan views'of twomodifications of a triangular floorsystem fo'r'buildings etc., arranged similarly to the ring floor systemof Figure 1. Figure 4 shows a plan layoutof a rectangular floorsystemfor buildings etc., having a similar arrangement to those justdescribed. Figure 5 is a-plan view ofv a modification of Figure 4, the.rectangles being formed by'means of joists arranged as illustrated, inthe section shown in Figure 6.

Figure 6 is acentral vertical transverse sec-, tion online 6-6 of Figure5.

Figure 7 shows a plan of a modified form of right-angular floor system,the loads being carried on each joist in turn near the ends thereof, thefinal or accumulated reactions being placed on the main beams ormarginal girders between the columns near their points of support.

Figure 8 shows a plan of a splayed floor systern, in which the endreactions of the floor supporting structural units are split up into twoor more reactions; the latter being transmitted to the marginal girdersor beams which extend between the columns at points near their points ofsupport.

Figure 9 shows a typical part plan layout of a geometricload-distribution system for a building.

Figure 10 is a plan view of a rectangular panel floor system using thegeometric ring load-distribution system.

Figure 11 is a plan layout of a floor panel in which the rings or stripsof floor are irregularly spaced with reference to each other.

Figure 12 is a transverse vertical section on line l2l2 of Figure 11 forsemi-detached and isolated rings, illustrating graphically the relativestrength of the rings shown in said figure.

Figure 13 is a transverse vertical section on line graphic illustrationof the relative strength of the rings.

Figure 14 is a plan of a floor panel, showing the arrangement ofreinforcing material, located near the top of the slab used for thepanel.

Figure 15 is a plan of a floor panel showing the arrangement ofreinforcing material located near the bottom of the slab used for thepanel.

Figure 16 is a vertical transverse half-section on line l6l6 of Figure15.

Figure 17 is a vertical transverse half-section on line I1|l of Figure15.

Figure 18 is a graphical diagram illustrating a triangular loading on asupporting beam.

Figures 1 to 8 illustrate several geometric systems, the fundamentalbasic principles of which are substantially the same in theory, namely,a geometric arrangement of the floor units which distributes the floorloads on to the supporting floor beams or marginal girders, inproportion to their size. It follows that the larger units being locatedfarthest from the approximate center of the supporting beam, thegreatest floor loads will be placed on the supporting beam near itspoints of support, thus making it possible to have lighter and shallowerbeams in the structure, as is well understood in the design of beams, incommon practice. 7

Assuming each geometric structural floor unit to be of unit width, itmay be readily seen that:

(1) The load on each of the rings or circular strips of floor I to 6inclusive as shown in Figure 1 is proportional to its radius.

(2) The load on each triangular strip of floor l, 8, 9 and In as shownin Figure 2 is proportional to its length,

(3) The load on each rectangular strip of floor ll, I2, I3 and M asshown in Figure 4 is proportional to its length.

Therefore the concentrations on the supporting floor beams, due to thereactions of these floor units increase from zero at the center to amaximum at the outer strips; in other words the beams or'marginalgirders, l5, l6 and H are loaded with a continuously increasing load,increasing uniformly from zero or a minimum at the center to a maximumat the outer strips or secondary beams, 6, I0, M respectively. AccordingI3--l3 of Figure 11, showing a similar to data obtainable from anystructural handbook, the maximum bending moment in a beam, simplysupported, and loaded with a triangular loading, increasing from zero atits center to a maximum at the ends, is only two-thirds of that for asimilar beam loaded with a uniform load over its which, according topresent methods of design, is

one of the most economical distributions in com mon use. Thisexplanation is based onv universally accepted principles.

In the case of a right angular floor system as shown in Figure 7, thefloor units, as illustrated by l8, I9, 20 and 2|, increase in size fromthe center ofthe panel until the boundary or marginal beams are reached.Each unit transmits its load near the ends of the unit directlysupporting it, until the final accumulated reactions are placed on thesupporting beams 22, 22 etc., near their points of support. It can bereadily seen that the bending moments involved are greatly reduced byreason of the floor loads being concentrated near the ends of thesupporting members.

The splayed beam system illustrated in Fig. 8, demonstrates in anelementary manner how the floor loads carried by astructural unit suchas 23 can be split up into two or more reactions 24, 25 and placed onthe supporting or marginal beams 26, 26 etc., near their points ofsupport, thus reducing the bending moment in the supporting floor beamaccording to the distance these loads are placed away from the centersof said beams or girders.

Figure 3 is a modification of Figure 2.

Figure 5 is a modified arrangement of Figure 4 in which the rectanglesare formed by means of continuous units as illustrated in section inFigure 6. The dotted portions of the floor units illustrated by 21, 28and 29 do not form part of the geometric system and do not carry thefloor 30 or the ceiling 3|.

Consider a case in which the whole floor is constructed of a pluralityof concentric rings or strips of suitable material, or of any othergeometric shape that can be mathematically analyzed and practicallyused: let Figure l represent a plan of a floor panel made up of a seriesof vsuch rings as outlined above, the floor being assumed to besymmetrical about the boundary beams or marginal girders and only halfthe rings being shown for the sake of convenience. As already explained,any other practical geometric shape would do. However, the ring isselected for this discussion, as it appears to possess certainadvantages over other shapes. Assume each ring to carry a strip of floorone foot wide, and the centers of each circular strip to be in exactfeet from the center of the beam; that is the annular center of thefirst ring or strip to be one foot from the center of the main ormarginal beams; the annular center of the second ring to be two feetfrom the center of the main beams and so on.

It may be easily proven that the reaction of each ring on the supportingbeam is proportional to the radius of the ring or strip. In other words,in the geometric load distribution system,

' located around the panel.

the supporting beam is loaded with a triangular continuous loading,increasing uniformly from zero at the center to a maximum at the outerrings.

In actual tests made to demonstrate the present system of construction,reinforced concrete construction was selected as being the best adaptedto fully demonstrate the principles of the geometric load-distributionsystem, because it was considered that if a solid slab would distributethe panel floor loads to the supporting beams, Without suflicienttransfer of the load in the shortest direction to cause rupture in theconcrete, the behaviour of semi-detached or isolated rings wouldnaturally follow. Steel boundary supporting beams usually placed betweenthe columns, simply supported, were decided upon as best fitted toillustrate the distribution of loads, due to the present system. Thetests disclosed that for working loads the distribution of loads to thesupporting beams is in substantial conformity with the geometricload-distribution theory described herein.

It can be seen from Figure 9 that the rings of the same radius are madestandard throughout the building for any particular floor loading; theirdetail is exactly similar whether it takes the form of slabreinforcement semi-detached or isolated rings. However it is importantto note that in the case of semi-detached or isolated rings the spacingof the rings depends on economical requirements of design; the smallerthe rings the greater the space between them according to therequirements of building specifications and codes.

Figure 10 shows a rectangular typical floor panel in which the ratio ofthe length and the breadth of the panel is in the substantial proportionof two to one. It can be seen that under this system the small beams arefully loaded and the longer beams are only partially loaded as theresult of these arrangements, and all the outer rings can be made intangential contact.

Figure 11 illustrates a typical layout for a semi-detached and isolatedring floor system, consisting of a series of irregularly spaced rings32, 38, 39, 40 and 4|, as opposed to a solid floor slab. It may be seenthat if the outer rings 32, 32 etc., are designed to carry all the loadon the central floor area 33, this load will be carried back near theends of the main supporting beams at points 34, 35 etc., through thereactions of these outer rings, thus reducing the bending moment in themain beams or girders 36, 36 etc., This reduction in bending moments isseen to be greater than in the case of the slab where each ring isassumed to carry a portion of the central floor area 33.

In the case of a solid floor slab, the central floor area 33 Figure l istreated as a suspended span for the purpose of design supported on thefour surrounding discs, each disc composed of a series of rings I to 6inclusive as shown in Figure 1, by means of a rectangular grid 42 orequivalent means as shown in Figure 15.

In the case of the isolated ring design the central floor area 33 issupported by the four outer rings 32, 32 etc., Figure 11, on a circularring 31, or other equivalent means of support.

Figures 12 and 13 represent graphically the size and stiffness of therings required for the panel as shown in Figure 11 in which figures therings 32, 33, 39, M! and El are shown in section.

It will be noted that the tangential rings 32, 32 etc., support eachother laterally at points of contact with each other preventing anytorque in the rings themselves.

It is important in the discussion We have in hand that the type ofconstruction be such that there is no tendency for the panelfloorloadings to travel to the main beams ormarginal girders in the directionnormal thereto. Therefore no members are introduced in the presentsystem whose strength and stiffness are such as to provide the means forcarrying such loads in a direction normal to the main beams, or towardstheir center.

In reinforced concrete construction, therefore, designed according tothe present system, no reinforcement is introduced to take care of anymoment or shear along lines normal to the main beams, and the torque inthe rings is assumed to be distributed throughout the disc comprised ofthe series of rings I to B inclusive in Figure 1.

Practical tests demonstrated the ring action in the slab and no evidencewas found to indicate any torsional shear failure in any part of theslab thus certifying to the correctness of the above assumptions.

In the case of any other type of construction consisting ofsemi-detached or isolated rings care must be taken not to employ anymethod or arrangement to prevent tilting of the rings and theaccompanying torque, which might constitute a system having considerablestrength and stiffness, in a direction normal to the main beams and thusprevent ring action and the desired distribution of loads on to the mainsupporting beams.

As illustrated in-Figure 9 by rings 44, 45 etc., where the arc of thering subtends central angles less than 180 degrees, the moments andtorques in such segments of rings decrease considerably as the centralangle diminishes, thus making additional savings in material possible inthe floor over those outlined above.

Practical tests show the ratio of the measured deflection to thecalculated deflections on the basis of triangular loading and uniformloading is 41; '73; 100. In other words the actual deflection is only0.562 of the calculated deflection for a triangular loading; asproportionally represented in Figure 18 and still further reductionfactors may be found to'be practical.

In the case of a, solidslab floor, the rings are assumed to be partiallyrestrained at the supports and laterally supported for their entireperimeter by the shear in the slab and no allowance made for torque.These assumptions are fully justified by practical performance as provedin actual tests. The maximum negative moment occurs at the supportingbeams on the line 46, 46 etc., Figure 14, and the maximum positivemoment occurs at the center of the half rings on the line 41, 51 etc.,Figure 15. The points of inflexion are assumed to be for practicalpurposes on a line 48, l8,'etc., Figures 14 and 15, making an angle ofsubstantially about 45 degrees with the diametral line of the rings,which lies parallel with the boundary beams.

The floor is designed for the maximum posilow, and providing hollowfillers beneath them, as at 12, 13 Fig. 12 of any material to keep theceiling level. The reinforcement 49, 50 etc., Figures 14 and 17,required to resist the negative moments is located near the top of therings and extends between the points of inflexion 48, 48 etc., on bothsides of the supporting beam as shown in Figure 14. The reinforcement5|, 52 etc., required to resist the positive bending moments in Figure15, is located near the bottom of the rings as is shown in said figure.This reinforcement 5|, 52 etc., is shown continuous at 53, 54 etc., inFigures 15 and 1'7 for the entire circle, for practical purposes, butneed only extend between the points of infiexion 48, 48 etc., Within anyparticular panel. Extra compression reinforcement is provided wherenecessary at 55, 56, 5'! etc., Figure 17 located at the bottom of theslab and extendingbetween the points of inflexion 48, 48 etc., Figure15, on both sides of the supporting beam as shown in said figure.

The reinforcement shown in Figure 15 by 58, 59 etc., located at thebottom of the floor and normal to the diagonals of the panel isintroduced to strengthen these areas of the floor and to tie the discstogether.

The reinforcement shown in Figure 14, at 65, 6| etc., located at the topof the floor around the columns, is introduced to strengthen the cornerarea of the panels, as initial failure tends to occur at the top of theslab near the ends of the beams, and roughly parallel thereto.

Figures 16 and 17 represent graphically the relative strength andstifiness of rings 62 to 61 inclusive for a solid floor.

In the case of semi-detached or isolated rings as shown in Figure 11,the rings are assumed to be partially restrained and designed to resistbending and torsional moments. Tests reveal that the torsion developedis only a small part of that indicated by free torsion equations.However, judgment must be used based on the strength and stiffness ofthe constructional methods employed.

As before mentioned, Figure 11 shows the layout for a panel constructedof semi-detached or isolated rings and Figures 12 and 13 give agraphical representation of the relative size and stiffness of the ringsrequired.

In the case of a solid floor, the central area 42, Figure 15 is designedexactly the same as an ordinary two-way slab and reinforcement l4, 14etc., is provided located near the bottom of the slab as shown in Figure16 or any other suitable means of support may be employed.

In the case of semi-detached or isolated rings, this area 33 Figure 11,may be supported on a curved ring 3'! as shown in Figure 11, or by anyother practical method.

In the description of the present system I have shown the outer rings tobe tangential in. order to best describe the distribution of loads tothe supporting beams, however in some instances it is advantageous tocontinue the systems farther by providing overlapping or interlockingrings 68, 69 etc., as shown in Figure 10.

These rings would be designed to carry a certain percentage of the floorload depending on the relative stiffness of the rings which overlap orinterlock, etc.,

While I have described this structure for floors of buildings, bridges,and other structures, it is readily seen that the present system ofconstruction and design may be readily applied for use in connectionwith roofs of any kind and particularly in connection with barrel andshell roof construction, similar to those used for skating rinks andother auditoriums. In the latter case the rings will naturally conformto the pitch or curvature of the roof being designed. In the extremecase where these rings are almost vertical they will act as a series ofarches distributing the loads almost vertically on the supporting beamsor Walls, increasing from a minimum at the center of the system ofrings, to a maximum at the rings farthest from the center of the ringsystem.

From the above description it will be seen that I have provided a systemof construction which accomplishes all the advantageous features set outin the preamble of this specification.

I claim:

1. An arrangement of floor panel construction, comprising a number ofmarginal girders connected to each other to form the outline of a panel,a. plurality of panel beams each supported on a marginal girder, andarranged to deliver panel load concentrations thereto, which increasefrom a minimum at a point intermediate the ends of the girder to amaximum nearer the ends. of the same.

2. An arrangement of floor panel construction, comprising a number ofmarginal girders connected to each other toform the outline of a panel,a plurality of panel beams each supported on a marginal girder at aplurality of points, and arranged to deliver the maximum panel loadconcentrations near the ends of said girder.

3. An arrangement of floor panel construction, comprising a number ofsupporting columns, a number of marginal girders carried by saidcolumns, a series of secondary beams arranged in circumscribed relationabout the panel, each being partially in said panel and partially in anadjacent panel and carried on one of the marginal girders, and aplurality of concentric groups of beams of smaller extent, which extendin both of said above described panels, each group having its centralpoint coincidental with that of one of the secondary beams, sucharrangement of panel beams being adapted to deliver load concentrationson. each of the marginal girders, which increase from a minimum near thecenter of each group of panel beams, to a maximum at points where theloads from the secondary beams are delivered to the marginal girders.

4. An arrangement of floor panel construction, comprising a number ofmarginal girders connected to each other to form the outline of a panel,a series of secondary beams arranged in circumscribed relation in thepanel, each mounted on one of the marginal girders, and a plurality ofconcentric groups of beams of smaller extent, each having its centralpoint coincidental with that of one of the secondary beams, sucharrangement of interior panel beams being adapted to deliver panel loadconcentrations on each of the marginal girders, which increase from aminimum near the center of each group of panel beams to a maximum at thepoints Where the loads from the secondary beams are delivered to themarginal girders.

5. An arrangement of floor panel construction comprising a main girder,a series of secondary beams, each having its central point on theapproximate longitudinal center line of said girder, and a plurality ofconcentric groups of beams of smaller extent, each having its centralpoint coincidental with that of one of the sec- Jond'ary beams, sucharrangement of secondary beams and beams of smaller extent being adaptedto deliver load concentrations on the main girder, which increase from aminimum near the center of each groupof beams toamaXimum at points wherethe loads from the secondary beams are delivered to the marginalgirders.

6. An arrangement of floor panel construction, comprising a number ofsupporting collumns, a number of marginal girders carried by saidcolumns, a' series of secondary beams arranged in circumscribed relationin the panel, each mounted on one of the marginal girders, and havingits central point intermediate the ends: of said girder, and a pluralityof concentric groups of beams of smaller extent, each having its centralpoint coincidental with that of one of the secondary beams, sucharrangement of interior panel beams being adapted to deliver panel loadconcentrations on each of the marginal girders, which increase from aminimum near the center of each group of panel beams to a maximum at thepoints where the loads from the secondary beams are delivered to themarginal girders.

7. An arrangement of floor panel construction for delivering floor panelconcentrations to the boundary beams at points adjacent the ends. ofsaid beams, comprising a number of connected boundary beams formingapanel therebetween, a series of rectangularly arranged floor panelbeams ultimately supported by the boundary beams, each beam of whichbeginning at the approximate center of the panel delivers its loadreactions near the ends of its adjacent and successive panel beams inturn, until the accumulated load reactions of all the interior panelbeams are delivered on the boundary beams in the manner specified.

8. An arrangement of floor panel construction, comprising a number ofsupporting columns, a number of marginal girders carried by saidcolumns, a series of arc-shaped secondary beams arranged incircumscribed relation in the panel, each mounted on one of the marginalgirders, and with its central point near the approximate center of saidgirder, and a plurality of concentric groups of arc-shaped beams ofsmaller extent, each having its central point coincidental with that ofone of the secondary beams, such arrangement of interior panel beamsbeing adapted to deliver pan-e1 load concentrations on each of themarginal girders, which increase from a. minimum near the center of eachgroup of panel beams, to a maximum near the ends of said girders.

9. An arrangement of floor panel construction, comprising a number ofsupporting columns, a number of marginal girders carried by saidcolumns, a series of angular-shaped secondary beams arranged incircumscribed relation in the panel, each mounted on one of the marginalgirders and with its central point near the approximate center of saidgirder, and a plurality of concentric groups of angular-shaped beams ofsmaller extent, each having its central point coincidental with that ofone of the secondary beams, such arrangement of interior panel beamsbeing adapted to deliver panel load concentrations on each of themarginal girders, which increase from a minimum near the center of eachgroup of panel beams, to a maximum near the ends of said girders.

10. An arrangement of floor panel construction, comprising a number ofsupporting columns, a. number of ,marginal girders carried by saidcolumns,- a series of U-shaped secondary beams arranged in circumscribedrelation in the panel, each mounted on one of the marginal girders, andwith its centrallpoint'near the approximate center of said girder, and aplurality of concentric groups of U-shaped beams of smaller extent, eachhaving its central point coincidental with that of one of the secondarybeams, such arrangement of interior panel beams being adapted to deliverpanel load concentrations on each of the marginal girders, whichincrease from a minimum near. the center of each group of panel beams,to a' maximum' near the ends of said girders. 1

11. An arrangement of floor panel construction, comprising a number ofsupporting columns, a number of marginal girders carried by saidcolumns, a series of secondary beams arranged in circumscribed relationin the panel, each mounted on one of the marginal girders, and with itscentral point near. the approximate cen ter of said girder, and aplurality of concentric groups of beams of smaller extent, each havingits central point coincidental with that of one of the secondary beams,reinforcing members in each of the panel beams near the top surfacethereof, for carrying the negative bending moments of such beams wherethey cross the marginal girders, and reinforcing members in each of thepanel beams near the bottom thereof for carrying the positive bendingmoments in said beams, such arrangement of interior panel beams beingadapted to deliver panel load concentrations on each of the marginalgirders which increase from a minimum near the center of each group of.panel beams, to a maximum near the ends of said girders.

12. An. arrangement of floor panel construction, comprising a number ofsupporting columns, a number of marginal girders carried by saidcolumns, a series of secondary beams arranged in circumscribed relationin the panel, each mounted on one of the marginal girders, and with itscentral point near the approximate center of said girder, and aplurality of concentric groups of beams of smaller extent, each havingits central point coincidental with that of one secondary beam,reinforcing members in. each of the panel beams near the top surfacethereof for carrying the negative bending moments of such beams wherethey cross the marginal girders, said members extending substantiallybetween the adjacent points of contraflexure in adjacent buildingpanels, and reinforcing members in each of the panel beams near thebottom thereof for carrying the positive bending moments in said beams,such members extending substantially between the points ofco-ntrafiexure within adjacent building panels, such arrangement ofinterior panel beams being adapted to deliver panel load concentrationson each of the marginal girders, which increase from a minimum near thecenter of each group of panel beams, to a maximum near the ends of saidgirders.

13. An arrangement of floor panel construction, comprising a number ofsupporting columns, a. number of marginal girderscarried by saidcolumns, a series of secondary beams arranged in circumscribed relationin the panel, each mounted on one of the marginal girders, and with itscentral point near the approximate center of said girder, and aplurality of concentric groups of beams of smaller extent,

each having its central point coincidental with that of one of thesecondary beams, reinforcing members in each of the panel beams near thetop surface thereof for carrying the negative bending moments of suchbeams where they cross the marginal girders, said members extendingsubstantially between the adjacent points of contraflexure in adjacentbuilding panels, and reinforcing members in each of the panel beams nearthe bottom thereof for carrying the positive bending moments in saidbeams, some of such members extending substantially between the pointsof contraflexure within adjacent panels and others of which extendthroughout the full length of the panel beams, such arrangement ofinterior panel beams being adapted to deliver panel load concentrationson each of the marginal girders, which increase from a minimum near thecenter of each group of panel beams, to a maximum near the ends of saidgirders.

14. In a floor panel construction having a number of marginal girdersforming the outline of the panel, an arrangement for delivering floorpanel load concentrations to the marginal girders which increase from aminimum at a point intermediate the length of each girder to a maximumtowards the ends of same, comprising means which are geometric shaped inplan view for transmitting to said girder loads due to panel loading insuch a manner that the maximum bending moment created in each of themarginal girders is less than if the panel load were delivered to thesaid girders so as to create a uniform loading on each girder.

15. An arrangement of floor beam construction for delivering loadconcentrations to a girder which increase from a minimum at a pointintermediate the length of the girder to a maximum towards the ends ofsame, comprising a plurality of beams which are geometric shaped in planview, mounted substantially in an axial manner and solely on the saidgirder, so that the load concentrations occur on the girder in the orderspecified.

16. An arrangement of floor panel construction for delivering floorpanel concentrations to the boundary beams at points adjacent the endsof said beams, comprising a number of connected boundary beams forming apanel therebetween, a series of rectangula-rly arranged floor panelbeams, ultimately supported on the boundary beams, each interior panelbeam beginning at the approximate center of the panel being arranged toreceive a plurality of unequal load reaction concentrations from itsadjacent panel beams, near the ends thereof, until the accumulated loadreactions from all the interior panel beams are delivered to theboundary beams in the form of concentrations in the manner specified.

REGINALD G. GODSON.

